In the prior art, ceramic disc operated valve assemblies are known, for example, single control ceramic disc valves are utilized in sanitary fittings such as for kitchen and bathroom fixtures, see for example, U.S. Pat. Nos. 3,433,264, 3,533,436, and 3,736,959. Dual control disc valves, either metal or ceramic are also known, see for example, U.S. Pat. Nos. 2,923,318, 3,040,770, 3,780,758, 3,807,455, 3,810,602, 3,831,621, 3,834,416 and 4,175,586. Ceramic valving elements have also been used in float actuated rotating valves, see U.S. Pat. No. 3,465,782. While the prior art discloses the use of both metal and ceramic discs to provide the valving function in a sanitary fitting, the cavitation and noise level generally attributed to the operation of such valves may be objectionably high. To reduce the noise levels when operating ceramic valves, various improvements have been suggested such as modifying the shape of the mixing chamber or by use of noise eliminating means, see for example, U.S. Pat. Nos. 3,433,264, 3,574,810, 3,951,169, 4,105,043 and 4,157,099.
It is an object of the present invention to provide a valve assembly in the form of a removable cartridge which may be utilized in both the hot and cold water valve positions in a sanitary fitting and is interchangeable therewith.
Another object of the invention is to provide a valve assembly in the form of a removable cartridge which utilizes a pair of discs, each disc having an orifice therein to provide the valving function in which a unique arrangement of the stem cooperates with an outlet hole or opening in the cartridge housing to provide an auxiliary means for throttling water flow downstream from the orifices formed in the valve discs.
It is another object of the invention to provide a removable cartridge assembly for use in a dual controlled sanitary fitting to provide the valving function in which each cartridge assembly includes an auxiliary valve means for throttling system arranged and constructed to operate in a prescribed patterned relationship to control the volume of water flow through the cartridge housing simultaneously with the volume of water flow through the disc orifices to provide a stepdown pressure drop and thereby inhibit cavitation and/or other objectionable noises associated with its operation.
A further object of the invention is to provide a ceramic disc valve assembly in the form of a cartridge including a housing and stem made of moldable plastic materials and when assembled comprises a tamper-proof unit which cannot be disassembled.
It is a further object of the invention to provide a ceramic disc cartridge assembly which is inexpensive to manufacture, easy to assemble and install in a valve body of a sanitary fitting.
The invention generally contemplates providing a replaceable valve assembly in the form of a cartridge adapted for insertion into a valve body of a sanitary fitting used for the control of water therethrough. The cartridge includes an axially, bored, cylindrical housing having open upper and lower ends, and an opening formed between the ends thereof; an elongated stem rotatably mounted therein; a first and second disc positioned within the housing and being in face-to-face movable contact and each disc having at least one inlet opening defining a water passageway therethrough. One end of the passageway of the first disc is positioned in fluid communication with the inlet opening defining a water passageway therethrough and is positioned so that relative movement between the discs will direct the at least one opening therein between a blocked, shut-off position with the openings out of alignment and the partially, and completely overlapped positions where water can flow through the discs. One of the discs is mounted in the housing and the other disc is connected to one end of the stem for rotation therewith. The cross-sectional area of the housing opening is substantially equal to the cross-sectional area of the at least one opening in the first and second discs. The stem and the housing cooperate with the housing opening to form auxiliary valve means which shifts from an opened to a closed position at substantially the rate as the at least one opening of the first and second discs. The auxiliary valve means provides a throttling of water flow downstream from the housing opening and the at least one opening formed in the discs which together operate in a patterned relationship to control the volume of water flow through the valve body simultaneously with the volume of water flow through the disc opening to provide a stepdown pressure drop and thereby inhibit cavitation and/or other objectionable noises associated with the operation of said valve.